Project description:We report the effect of oxygenation state in lactose grown escherichia coli producing recombinant proteins. To shed more light on the mechanistic correlation between the uptake of lactose and dissolved oxygen, a comprehensive study has been undertaken with the E. coli BL21 (DE3) strain. Differences in consumption pattern of lactose, metabolites, biomass and product formation due to aerobiosis have been investigated. Transcriptomic profiling of metabolic changes due to aerobic process and microaerobic process during protein formation phase has been studied and the results provide a deeper understanding of protein production in E. coli BL21 (DE3) strains with lactose based promoter expression systems.This study also provides a scientific understanding of escherichia coli metabolism upon oxygen fluctuations.
Project description:Microarray hybridization of cDNA libraries obtained from exponentially growing or heat-shocked AW1.7 or GGG10 cultures was performed to compare gene expression of these two strains. Expression of selected genes from different functional groups was quantified by quantitative PCR (q-PCR). DnaK, 30S and 50S risobomal subunits were overexpressed in E. coli GGG10 relative to E. coli AW1.7 upon heat shock at 50°C, indicating improved ribosome stability. The outer membrane porin NmpC and several transport proteins were overexpressed in exponentially growing E. coli AW1.7.
Project description:The objective of this work was to design an improved host platform for recombinant protein expression in E. coli. The approach involves first to create a library of the E. coli genomic DNA in different expression vectors and screen for probable transcripts which may lead to slow growing colonies and also simultaneously over-expression of recombinant proteins. To observe its effect on host performance, these genes were knocked out from the E. coli genome. A CG2 strain has been created by knocking in vhb gene gene downstream of the acetate promoter and knocking down ribB gene in DH5α and transformed with Recombinant GFP cloned in pBAD33.
Project description:The intention of this study is to analyse the effect of antibiotics on the gene expression of Escherichia coli. Shaking-flask cultivations of Escherichia coli K12GFP-UTL2 were carried out with a medium containing nalidixic acid. Cultures with antibiotic-free medium, which were run in an identical way, served as reference. Samples were taken at different times during the cultivations, the RNA was isolated and hybridised on whole genome yeast microarrays. Keywords: Influence of toxins on gene expression in E. coli
Project description:We investigated the effect of the T4 MotB protein on E. coli gene expression. E. coli BL21 (DE3) containing either pNW129 or pNW129-MotB were grown to early log phase (OD600 ~ 0.3) then induced with 0.2% arabinose for 20 minutes. T4 phage added to the culture at MOI10. Cells were then harvested at 5 min.
Project description:Escherichia coli (E. coli) amine oxidase (ECAO) encoded by tynA gene has been one of the model enzymes to study the mechanism of oxidative deamination of amines to the corresponding aldehydes by amine oxidases. The biological roles of ECAO have been less addressed. Therefore we have constructed a gene deletion Escherichia coli K-12 strain, E. coli tynA-, and used the microarray technique to address its function by comparing the total RNA gene expression to the one of the wt. Our results suggest that tynA is a reserve gene for stringent environmental conditions and its gene product ECAO a growth advantage compared to other bacteria due to H2O2 production.
Project description:To get a high resolution understanding of the effect of Fur on global gene expression, we compared by high-resolution RNAseq the transcriptomes of a wild-type E. coli K-12 strain and its Fur deletion derivative grown in minimal medium with or without supplementation of iron. Three independent total RNA extraction and RNAseq assays were performed for each strain in each condition.
Project description:DNA microarray experiments were used to compare gene expression profiles of untreated and 5-azacytidine treated Escherichia coli at both logarithmic phase and early stationary phase The goal was to determine the effect of cytosine DNA methylation loss on gene expression (5-azacytidine is a methylation inhibitor)
Project description:The purpose of this study is to determine whether the presence of pathogenic Escherichia coli in colon is associated with psychiatric disorders.
